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Old 18th August 2006, 04:22 PM   #41
anatech is offline anatech  Canada
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Hi Mike,
They are on VDE/UL/CSA certification. I would help if they used their heads once in a while though. Mind you, many times the safety organisations can be fairly stupid too and force these "gifts" on us.

If these parts go open (and they will in a fault), it will guarantee excessive current in the output stages. Like tons of uncontrolled current. There would be high current in a failure, but not like this unless an output shorted.

They will probably not discolour and confound a technician without experience, or the poor guy without a diagram (thanks by the way!).

-Chris
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Old 18th August 2006, 11:46 PM   #42
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Default Re: Re: Examples:

Quote:
Originally posted by mikeks
Sony TAN-R1:
http://www.thevintageknob.org/SONY/s...NR1/TANR1.html
Odd that Sony refers to this as SEPP Class A, but looking at the
schematic I don't see it, I only see complementary followers.
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Old 19th August 2006, 01:25 AM   #43
mikeks is offline mikeks  United Kingdom
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SEPP=Single Ended Push-pull
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Old 23rd August 2006, 01:58 AM   #44
mikeks is offline mikeks  United Kingdom
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Quote:
Originally posted by mikeks



see patent
The circuits in this patent cannot work as advertised, in any case, as the relay will simply chatter on and off-if at all.

A latch is mandatory.
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Old 27th August 2006, 02:09 AM   #45
mikeks is offline mikeks  United Kingdom
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Thumbs down It gets worse...

Sony's last so-called ''current feedback'' ''high-end'' offering uses a crude shortcircuit-only arrangement, which is supposed to VERY prematurely limit each of five pairs/channel of 2SK1530/2SJ201 MOSFETs to just 6.7A regardless of Vds (but doesn't in practice because of the relay's drop-out time-constant), leaving the MOSFETs unprotected for Vds>20V and Id<=6.7A.

Abominable!

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Old 27th August 2006, 12:34 PM   #46
mikeks is offline mikeks  United Kingdom
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Exclamation In fact...

...the power output of this amp could be readily and usefully increased, from its alleged four ohm capacity, to accomodate one ohm loads, at least on a transient basis, while simultaneously providing foolproof SOA protection for its output stage.
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Old 27th August 2006, 05:46 PM   #47
anatech is offline anatech  Canada
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Hi Mike,
What a dum arrangement!

-Chris
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Old 27th August 2006, 08:33 PM   #48
mikeks is offline mikeks  United Kingdom
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Quote:
Originally posted by anatech
Hi Mike,
What a dum arrangement!

-Chris
..and for $14000 to boot..
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Old 27th August 2006, 09:04 PM   #49
anatech is offline anatech  Canada
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Not from my wallet! But it is shiny ...
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